import { describe, expect, it } from 'vitest';

import { BinaryReader } from '../binary/BinaryReader.js';
import {
  readCompactU64,
  readFssHttpExGuid,
  readFssHttpStreamHeader,
} from './primitives.js';

describe('FSSHTTPB primitives', () => {
  it.each([
    [[0x00], 0n],
    [[(0x5a << 1) | 1], 0x5an],
    [[0xd2, 0x48], 0x1234n],
    [
      [0x80, 0xef, 0xcd, 0xab, 0x89, 0x67, 0x45, 0x23, 0x01],
      0x0123_4567_89ab_cdefn,
    ],
  ] as const)('decodes compact unsigned integer %j', (input, expected) => {
    const reader = new BinaryReader(Uint8Array.from(input));
    expect(readCompactU64(reader)).toBe(expected);
    expect(reader.remaining).toBe(0);
  });

  it('rejects a truncated extended GUID at the original absolute offset', () => {
    const reader = new BinaryReader(
      Uint8Array.from([0, 0, 0x80, 1, 2]),
      2,
      3,
      'test ExGuid'
    );
    expect(() => readFssHttpExGuid(reader)).toThrowError(
      expect.objectContaining({ code: 'BOUNDS_EXCEEDED', offset: 3 })
    );
  });

  it('rejects stream-object end markers where a start is required', () => {
    const reader = new BinaryReader(Uint8Array.from([0x05]));
    expect(() => readFssHttpStreamHeader(reader)).toThrowError(
      expect.objectContaining({
        code: 'INVALID_STRUCTURE',
        offset: 0,
        structure: 'FSSHTTPB stream object header',
      })
    );
  });
});